布拉格衍射型冷原子干涉重力仪关键实验条件分析

Analysis on key experimental requirements of Bragg diffraction-based cold atom interferometry gravimeter

介绍了一种基于n阶布拉格衍射的新型冷原子干涉重力仪,可以进一步提高现有拉曼跃迁型原子干涉重力仪的测量灵敏度和稳定度。在介绍布拉格衍射型原子干涉重力仪基本原理的基础上,建立了原子平行驻波入射的时间型布拉格衍射冷原子干涉重力仪理论模型,分析了实验所需的关键条件,包括原子团纵向温度、布拉格激光直径、曲率半径、频率、强度以及时序等。与已有实验数据的对比结果表明:所建模型合理,所得结论能够为实际构造一台布拉格衍射型冷原子干涉重力仪提供有意义的指导。

A new type of cold atom interferometry gravimeter based on Bragg diffraction was presented,which is able to increase the gravity measurement sensitivity and stability of common Raman atom gravimeters significantly.By comparing with Raman transition,the principles and advantages of Bragg diffraction-based atom gravimeters were introduced.The theoretical model for a time-domain Bragg atom gravimeter with atomic incident direction parallel to the wave vector of Bragg lasers was constructed.Some key experimental requirements for an nth-order Bragg diffraction-based atom gravimeter were deduced,including the temperature of atom sources,the diameter,curvature radius,frequency,intensity,and timing sequence of Bragg pulses,etc.The analysis results were verified by the existing experimental data in discussion.The presented theoretical model and conclusions provide a meaningful reference for the understanding and construction of a Bragg diffraction-based cold atom gravimeter.